While there are many conceivable ways to carry a bike on the exterior of a vehicle, one general classification would encompass roof-mounted bike carrier systems.
Basically, there are two types of bike carrier systems being used today to transport bikes on the rooftop of a vehicle. There is the fork-mount bike carrier system and the upright bike carrier system.
In the first type of bike carrier system, the fork-mount bike carrier system, the front wheel of the bicycle must be removed so that the front wheel forks can be mounted and secured into a holding device. By securing the front wheel forks, the bicycle is further stabilized. The rear wheel remains attached to the bike and is secured to the bike carrier via a wheel holding device.
In the second type of bike carrier system, the upright bike carrier system, the user can transport a bicycle without having to remove the front wheel. This means that the bike will be in a ride-ready configuration when removed from the upright bike carrier system. With this system, both the front and rear wheels are secured to the bike carrier via a wheel holding device. For further security and stability, the bike can be stabilized through the use of a support arm that engages the front down tube of the bicycle frame.
However, both of these bike carrier systems have some shortcomings. For example, one of the disadvantages of the first type of system, the fork-mount bike carrier system, is that it is very inconvenient and time consuming to remove the front wheel from the bike whenever the bike is mounted to the system, and to put the front wheel back on whenever the bike is removed from the system.
Furthermore, one of the disadvantages of the second type of system, the upright bike carrier system, is that the support arm used to secure and stabilize the bike is designed to hold a traditionally-shaped cylindrical front down tube of a bike frame. However, many of the newer and technologically advanced bicycle frame designs utilize various different materials and non-cylindrical shapes for the front down tube of the bike frame.
Thus, the currently available upright bike carrier systems would be unable to accommodate any of these newer bikes, which utilize various non-cylindrical shapes for the front down tube of the bike frame. A different, custom designed, support arm would be required every time a bike of differing shape needs to be secured and stabilized on an upright bike carrier system.
In addition, another disadvantage of the upright bike carrier system is that an excessive retaining force exerted by the support arm on the front down tube of the bicycle frame could crush or deform the front down tube.
Therefore, there is a need for an improved bike carrier system which would enable a user to transport a bike in a ride-ready configuration, and would further enable that user to attach a bike, of any shape, to the bike carrier without the need for specially shaped supporting arm adapters, and without concern for damage to the bicycle frame.